gdb/ChangeLog:
* solib-svr4.h (struct link_map_offsets): Add l_ld_offset and
l_ld_size fields.
* solib-svr4.c (struct lm_info): Add l_addr field.
(LM_ADDR_FROM_LINK_MAP): Renamed from LM_ADDR.
(HAS_LM_DYNAMIC_FROM_LINK_MAP): New.
(LM_DYNAMIC_FROM_LINK_MAP): New.
(LM_ADDR_CHECK): New. Use it instead of LM_ADDR.
(svr4_current_sos): Initialize l_addr. Adjust.
(svr4_relocate_section_addresses): Adjust.
(svr4_ilp32_fetch_link_map_offsets): Define new members.
(svr4_lp64_fetch_link_map_offsets): Likewise.
* solib-legacy.c (legacy_svr4_fetch_link_map_offsets): Likewise.
* mipsnbsd-tdep.c (mipsnbsd_ilp32_fetch_link_map_offsets): Likewise.
(mipsnbsd_lp64_fetch_link_map_offsets): Likewise.
* Makefile.in (solib-svr4.o): Depend on $(elf_bfd_h).
gdb/testsuite/ChangeLog:
* gdb.base/prelink.exp: New test.
* gdb.base/prelink.c, gdb.base/prelink-lib.c: New sources.